I. Disaster Preparedness

Chapter I

Disaster Preparedness

In this chapter you will learn about

Disasters and disaster workers: What defines a disaster, and who makes up the disaster workforce.

Disaster threats: Characteristics of various types of disasters and the potential for occurrence in your area.

Impact on the infrastructure: The potential effect of disasters on transportation, electrical service, telephone communication, fuel and water supplies, and emergency services.

Structural and nonstructural hazards: Potentially hazardous conditions in various types of structures and their contents during a disaster.

Safety precautions during a disaster: What to do if you are inside, outside, or driving a vehicle.

Individual and worksite preparedness: How you can prepare in advance to reduce structural and nonstructural hazards and survive the initial period after a disaster.

Community preparedness: How a community can prepare in advance to respond in a disaster situation.

1

CERT Training: Participant HandbookPage I-1

I. Disaster Preparedness

Disasters And Disaster Workers

What Is A Disaster?

According to Webster’s Dictionary, a disaster is

Any event that overwhelms existing resources to deal with the event.

Disasters may be natural or caused by human actions, may occur in any season of the year, and may cover a limited or a wide-ranging geographic area. The following are some examples of the wide range of events that may reach disaster proportions:

Earthquake

Hurricane

Tornado

Blizzard

Flood

Act of terrorism (e.g., bombing)

Civil disturbance (e.g., riot)

Hazardous materials incident

What Is A Disaster? (Continued)

Whatever the cause, disasters have several key elements in common:

The event is relatively unexpected, with little or no prior warning or opportunity to prepare.

Available personnel and emergency services may not be available during the initial stages of a disaster because of demands for their services.

Lives, health, and the environment are endangered.

Who Are “Disaster Workers”?

A variety of services, agencies, and programs work together to provide emergency services and disaster assistance to local residents after a disaster event. However, these service providers cannot be everywhere at once, and initial needs may be greater than they can handle immediately with available resources. During these initial hours after a disaster, when damage is heavy or widespread and emergency services are stretched thin, many people are called upon to provide assistance to those around them.

Individuals and families help themselves. Neighbors help neighbors. Coworkers help each other. Able-bodied people turn out to offer their services to the emergency services workers. Volunteers play an extremely important role in reducing the death, injury, and damage in the period immediately after a disaster. They bring a wide variety of skills and experience to the task, and through teamwork can help build a vital network that links all parts of the disaster area. (See Figure I-1 on page I-5.)

Who Are “Disaster Workers”? (Continued)

Figure I-1. Disaster Workers

Disaster Threats

The potential threat of different types of disasters varies across the United States. This section provides overviews of the following types of disasters:

Earthquakes

Hurricanes And Coastal Storms

Tornadoes

Floods

Hazardous Materials Accidents

You may wish to highlight key parts that relate especially to your area, as outlined by your instructor.

Earthquakes

Introduction

Earthquakes are a shaking or trembling of the earth, caused by underground volcanic forces or by breaking and shifting of rock beneath the surface. Although the area of greatest earthquake risk is the west coast, where tectonic activity occurs along the San Andreas fault, other areas of the United States are also at risk of earthquakes. For example, Memphis, Tennessee and St. Louis, Missouri are located along major faults. The map in Figure I-2 on page I-9 shows locations of moderate or greater earthquakes throughout the U.S.

Earthquake Classifications

Earthquakes are classified as small, moderate, major, or great based on the Richter scale (a measure of energy released during the quake). The Richter scale has a logarithmic base, so each increment on the scale is multiplied by a factor that is 10 times larger than the previous factor. (For example, an earthquake of magnitude 8.6 would not be twice as violent as one of 4.3, but rather would be 10,000 times worse.) Although there are other methods of determining earthquake intensity and magnitude, the Richter scale is the most widely used method today. Earthquake classifications based on Richter scale magnitudes are shown in the table below.

Classifications / Richter Scale Magnitudes
Small / 5.05.9
Moderate / 6.06.9
Major / 7.07.9
Great / 8.08.9

Table I-1. Earthquake Classifications

Earthquake Prediction

Although it is still impossible to predict earthquakes accurately, scientists have been able to derive some probabilities about future earthquakes in the United States, including:

Areas along the west coast are at risk for earthquakes every day.

Major earthquakes appear to occur in cycles of between 50 and 275 years.

It is likely that a major earthquake will hit California and perhaps other parts of the U.S. in the next decade or two.

Earthquake Prediction (Continued)

1

Figure I-2. Sites Of Moderate Or Greater Earthquakes

Hurricanes And Coastal Storms

Introduction

Hurricanes are violent areas of low pressure forming in the tropical Atlantic Ocean from June to November. (Similar Western Pacific Ocean storms are called typhoons.) Hurricanes have winds of 75 miles per hour or more and are accompanied by torrential rains andalong coastal regionsa storm surge. Although coastal storms may have hurricane-force winds and may cause similar kinds and amounts of damage, they are not classified as hurricanes because they do not originate in the tropics. Together, hurricanes and coastal storms cause billions of dollars in damage annually in the United States.

Hurricane Classifications

Hurricane strength is classified using the Saffir-Simpson Hurricane Damage Potential Scale. This scale correlates hurricane strength to barometric pressure, windspeed, and storm surge as shown in the table below.

Category / Barometric
Pressure (Inches) / Windspeed
(Miles Per Hour) / Storm
Surge (Feet)
I - Minimal / Above 28.94 / 74-95 / 4-5
II - Moderate / 28.50-28.91 / 96-110 / 6-8
III - Extensive / 27.91-28.47 / 111-130 / 9-12
IV - Extreme / 27.17-27.88 / 131-155 / 13-18
V - Catastrophic / Less Than 27.17 / More Than 155 / More than 18

Table I-2. Hurricane Classifications

Hurricane Prediction

On average, the coasts along the Gulf of Mexico and the Southeastern seaboard are struck by more than five hurricanes each year. Although meteorologists now have many ways in which to predict hurricanes, tracking storm movement and landfall remains an inexact science. The National Hurricane Center, located in Miami, Florida, has predicted that 1992 was the first year of a 10-year cycle of severe hurricane activity. The map in Figure I-3 on page I-12 shows areas of high hurricane and coastal storm activity.

Hurricane Prediction (Continued)

2

Figure I-3. Areas Of High Hurricane And Coastal Storm Activity

Tornadoes

Introduction

Tornadoes are powerful, circular windstorms that may be accompanied by winds of 200 or more miles per hour. Tornadoes may range in width from several hundred yards to more than one mile across. Although tornadoes may occur throughout most of the United States, areas in the Midwest and South are particularly susceptible to tornado activity. Parts of Texas, Oklahoma, Kansas, Missouri, Nebraska, Mississippi, Alabama, Georgia, and Florida are at highest risk of tornado strike. (See the map in Figure I-4 on page I-15 showing tornado incidence.)

Tornado Classifications

Tornadoes are classified using the Fujita Wind Damage Scale. This scale correlates damage with windspeed, as shown in the table below.

Category / Windspeed
(Miles Per Hour) / Damage
F0 / Up to 72 / Light
F1 / 73-112 / Moderate
F2 / 113-157 / Considerable
F3 / 158-206 / Severe
F4 / 207-260 / Devastating
F5 / More than 260 / Incredible

Table I-3. Tornado Classifications

Tornado Prediction

With the help of sophisticated radar and other measures, meteorologists are now able to predict when favorable conditions for tornado formation exist and are better able to warn the public. However, even given an average of 700 confirmed reports of tornadoes each year in the United States, many remain unreported.

Tornado Prediction (Continued)

3

Figure I-4. Areas Of High Tornado Incidence

Floods

Introduction

A flood occurs any time a body of water rises to cover what is usually dry land. Floods have many causes, including heavy rain, spring snowmelt, hurricanes and coastal storms, and dam or levee failure. When flooding occurs, affected areas may sustain damage to structures and personal property, as well as severe damage to the environment in the form of soil erosion and deforestation, and damage to utilities and transportation systems. Flash floods, for which there is little or no warning, cause great risk to humans and animals. Land along rivers and streams, lakeshores, and coastlines are particularly susceptible to flooding. Under some conditions, however, even inland areas that are not normally threatened by flooding may be immersed.

Flood Classifications

Floods are measured according to the heights the waters reach. Their magnitude is based on the chances that water flow will equal or exceed a certain level on a recurring basis.

Flood Prediction

Satellite technology combined with river forecast centers and hydrologic service areas enable meteorologists to predict flood occurrence and severity with reasonable accuracy and provide warnings to those in high-risk areas. On average, rivers overflow their normal boundaries once every 2 years. Severe coastal flooding, however, can result in conjunction with any hurricane or coastal storm, the track of which cannot be predicted with complete accuracy. Clearly, the risk of damage or injury resulting from floods cannot be downplayed.

Blizzards

Introduction

The National Weather Service defines a blizzard as considerable falling or blowing snow accompanied by winds of 35 miles per hour or more. Blizzards are also accompanied by frigid temperatures and extremely limited visibility. Blizzards in the United States occur most frequently in the northern Midwestern States but may occur inland of Atlantic coastal storms and at high altitudes in the Western States. When blizzards occur, much of the infrastructure in the affected area may be disrupted for several days.

Blizzard Classification

Blizzards are classified by their windspeed and concurrent visibility. Blizzard classifications are shown in the table below.

Type / Windspeed / Visibility
Blizzard / 35 - 44 miles per hour / Less than 500 feet
Severe Blizzard / 45 miles per hour
or greater / Approaching zero

Table I-4. Blizzard Classifications

Blizzard Prediction

With the help of satellites and other methods, meteorologists can predict when conditions are favorable for blizzard conditions to develop, which allows them to issue blizzard watches and warnings to the public. It remains impossible, however, to predict blizzards with complete accuracy or to predict the exact track that a storm will follow.

Hazardous Materials Accidents

Introduction

According to the Resource Conservation and Recovery Act of 1976, a hazardous material is any product that corrodes other materials, explodes or is easily ignited, reacts strongly with water, is unstable when exposed to heat or shock, or is otherwise toxic to humans, animals, or the environment. While the United States has a body of law governing the safe handling, transport, and disposal of hazardous materials, accidents can and do occur throughout the country on a regular basis. Additionally, while the risk of exposure to radioactive materials in nuclear power facilities, mining operations, and storage facilities is strictly regulated, it remains possible for a radioactive materials incident to occur.

Hazardous Materials Classifications

Hazardous materials are not classified in the same way as natural hazards. Also, hazardous materials are classified differently depending on whether they are being stored or transported. Both classification systems are discussed more fully in Chapter II: Disaster Fire Suppression.

Hazardous Materials Accident Prediction

While there is no way to predict hazardous materials accidents, certain areas are at some degree of risk, including those located near interstate highways; manufacturing, storage, or disposal facilities; and nuclear power facilities. Prevention of accidents, rather than prediction, is central to avoiding potential damage, loss, or other contamination from hazardous materials.

Impact On The Infrastructure

Introduction

When a disaster occurs, it has a cascading effect because of its impact on the infrastructure: transportation, utilities, communications systems, fuel supplies, and water suppliesthe services and delivery systems on which we depend. When one of these important elements in our support system breaks down, it has a domino effect, causing other elements to falter. When multiple elements break down, the effect can be crippling. Some of the ways in which the infrastructure can be affected in a disaster or emergency are shown in the table below.

Service / Effect
Transportation / Inability to get emergency service personnel into the affected area.
Inability to transport victims away from the area.
Electrical / Increased risk of fire and electrical shock.
Possible disruption to transportation system if downed lines are across roads.
Telephone / Lost contact between victims, service providers, and family members.
System overload due to calls from or to friends or relatives.
Water / Disruption of service to homes, businesses, and medical providers.
Inadequate water supply for firefighting.
Increased risk to public health if there is extensive damage to the water supply or if it becomes contaminated.
Fuel Supplies / Increased risk of fire or explosion from ruptured fuel lines.
Risk of asphyxiation from natural gas leaks in confined areas.

Table I-5. Possible Effects Of Damage To The Infrastructure

Emergency Services

Each instance of damage to the infrastructure may severely restrict the abilities of police, fire, and paramedic services to provide service following a disaster. Some types of damage and their effects on emergency services are shown in the table below.

Type Of Damage / Effect On Emergency Services
Road / Inability to assess damage accurately.
Ambulances prevented from reaching victims and/or victims prevented from reaching emergency medical services.
Police prevented from reaching areas of civil unrest.
Fire departments prevented from getting to fires.
Flow of needed supplies is interrupted.
Structural / Damaged hospitals unable to receive patients.
Increased risk of damage from falling debris.
Disrupted Communication / Victims unable to call for help.
Coordination of services is hampered.
Fuel Line Damage / Fire and paramedic services overburdened.
Disrupted Water Service / Firefighting capabilities restricted.
Medical facilities hampered.

Table I-6. Possible Effects Of Damage On Emergency Service Providers

Service Priorities

Because emergency services are likely to have inadequate resources to meet the needs in a disaster situation, those resources must be applied according to highest priority need:

Police:Establish order and safe ingress/egress to and from the disaster area.

Fire:Suppression of major fires.

Paramedic:Life-threatening injuries.

Lower priority needs may have to be met in other ways.

Structural And Nonstructural Hazards

Introduction

During and following a disaster, damage to building structures presents one of the greatest hazards. Damage will vary according to the type of disaster, the type and age of the structure, and location in relation to the disaster center. The following is an overview of disaster hazards related to building structures and their contents.

Hazards Related To Structure Type

High-Rise And Apartment Buildings

Engineered buildings, such as most high-rise structures, have performed well in earthquakes and other disasters. Older high-rise buildings with steel and concrete construction are more susceptible to damage than the newer ones which use curtain construction and prefabricated panels. Primary hazards in and around high-rise buildings include:

Broken glass.

Falling panels.

Hazards in and around apartment buildings depend largely on the age and condition of the structure. Hazards may include:

Collapsing walkways and stairways.

Crumbling cornices and other trim.

Broken glass.

Detached Homes

Age, type of construction, and type of disaster are major factors in potential damage to detached homes and garages. Homes built before 1940 generally were not bolted to the foundation, making them subject to being shaken, blown, or floated off their foundations. Older homes constructed of unreinforced brick are less stable than newer construction. Porches without support beams may collapse. Damage to single homes from tornadoes and hurricanes can range from little damage to total destruction. Following a disaster event, there is the potential for further collapse and fire due to ruptured gas lines.

Mobile Homes

When mobile homes are displaced in a disaster (whether earthquake, storm, flood, or other), utility connections are easily damaged, and broken gas lines may cause fires.

Other Public Places

Malls, sports arenas, airports, places of worship, and other places where people may gather may pose hazards in some types of disasters. For example, in an earthquake, overhead structures may collapse. Widespread panic in large crowds can result in casualties.

Nonstructural Hazards

Fixtures and items within a home, garage, or office can pose hazards during or after a disaster event. The following are examples of some of the nonstructural hazards that may be encountered:

Gas line ruptures from water heaters or ranges displaced by shock or water.

Damage from falling books, dishes, or other cabinet contents.

Risk of injury or electric shock from displaced appliances and office equipment.

Hazardous products within reach of children.

Disaster Hazard Mitigation

Introduction

Regardless of the event or the amount of warning offered, there are safety precautions that one can take to reduce or prevent injury. These measures include:

Personal safety.

Home and worksite preparation.

Community preparation.